I always worry about these ideas, they seem good in theory, but in reality you can just end up with a cane toad problem..i.e. when the algae has covered all the oceans we have no pollution...but also no fish....
anywho...maybe we can just set fire to the algae if it gets out of control...

.. maybe we can just set fire to the algae if it gets out of control...

Or we can try this on a trial basis, and scale it up if it seems to be working. When the algae sinks, carrying the carbon to the bottom of the ocean, it takes the iron with it. So when we stop putting the iron in, the amount of algae returns to normal, so it is unlikely to "get out of control." Sure, there might be some side effects, but there will probably be even bigger side effects if we do nothing. And the side effects are not all bad: it should increase the amount of fish that can be sustainably harvested.

And the side effects are not all bad: it should increase the amount of fish that can be sustainably harvested.

The 2 side effects mentioned in the article both kill fish. Toxic algal blooms poison fish, either causing them to grow abnormally or death. Depleted oxygen levels does the same thing to the fish as it does to you, suffocation.

In many places of the world, nutrient-rich deep-ocean water rising to the surface causes natural algal blooms. Algae eating fish like sardines flock to them and breed up in huge numbers, and form the basis for many of the world's fisheries.Indeed, practically all fish either eat algae, or eat marine life that eats algae.So fertilising the oceans is just as likely to produce schools of fish and new rich fisheries to harvest as fish kills. In reality, it would probably cause both: overpopulation of fish that

Or we can try this on a trial basis, and scale it up if it seems to be working. When the algae sinks, carrying the carbon to the bottom of the ocean, it takes the iron with it.

Well, it's not that simple. The algae we cause to bloom consumes nutrients that would have been consumed by other algaes. Nor is the ocean bottom dead - dumping that massive amounts of iron and algae into them is not going to be without effect.

I always worry about these ideas, they seem good in theory, but in reality you can just end up with a cane toad problem..i.e. when the algae has covered all the oceans we have no pollution...but also no fish....

anywho...maybe we can just set fire to the algae if it gets out of control...

The underlying problem is, people are willing to consider anything - except addressing the cause of the problem.

The underlying problem is, people are willing to consider anything - except addressing the cause of the problem.

The underlying problem is too hard to solve with current technology. According to Hansen et al, we need to get the CO2 levels down to 350ppm if we want to be safe. This means, not only must we immediately stop adding CO2 to the atmosphere, we also need to remove some of it.

So think of all the things you do that add CO2 to the atmosphere (of course breathing doesn't count because it is net neutral). That is pretty near everything. Imagine if we stopped all that immediately. Not only would we have to switch over to nuclear, we'd also have to stop driving. And flying. Good luck at that, it would be economic suicide.

No one is willing to do that, so the only proposals are things like Kyoto, which did little, or Copenhagen, which would have done nothing.

"No one is willing to do that, so the only proposals are things like Kyoto, which did little, or Copenhagen, which would have done nothing."

It's not that they're UNWILLING to do that, at all. It's that it would be so enormously expensive, they want SOLID proof before going down that road. Evidence that has so far not been forthcoming.

Seriously: the cost of sequestering enough carbon dioxide to prevent 0.5 degree C warming over the next hundred years, has been estimated to be about the same as the cost of completely eliminating world hunger, even after considering inflation.

The underlying problem is too hard to solve with current political will. Nobody is suggesting we change everything overnight but considering we burn 5 billion tons of coal/yr and that every fuctioning coal plant on the planet has been built (and in many cases rebuilt) since I was born, 50yrs is plenty of time to convert to renewables. If it wasn't for vested interests this would happen in a similar way to how the current FF infrastructure was built (hardly noticable to the casual observer). If you want more

The underlying problem is too hard to solve with current technology. According to Hansen et al, we need to get the CO2 levels down to 350ppm if we want to be safe. This means, not only must we immediately stop adding CO2 to the atmosphere, we also need to remove some of it.

Hansen is someone who spreads FUD to gain notoriety. Read the IPCC instead. It contains a lot of scary imagery too, but ultimately, you can find a simple cost/benefit analysis, which sums it up:

For increases in global average temperature of less than 1 to 3ÂC above 1980-1999 levels, some impacts are projected to produce market benefits in some places and sectors while, at the same time, imposing costs in other places and sectors. Global mean losses could be 1 to 5% of GDP for 4ÂC of warming, but regional losses could be substantially higher.

Limited and early analytical results from integrated analyses of the global costs and benefits of mitigation indicate that these are broadly comparable in magnitude, but do not as yet permit an unambiguous determination of an emissions pathway or stabilisation level where benefits exceed costs.

The idea that we should dump vast quantities of iron into the ocean in order to mitigate a potential problem that amounts to little more a slight reduction in global GDP is ludicrous. Algal blooms and tinkering with iron content of the ocean is far more dangerous than rising CO2 levels, Hansen's cataclysmic fantasies notwithstanding.

This. The falling sky proponents love to pretend that it's all a done deal yet the entire model fails to adequately account for previous warm periods, nor the fact that CO2 is merely plant food. (photosynthesis, how does it work?)

Even if you accept the premises that 1) the climate is warming and 2) that human produced CO2 is to blame, taking the entire thing a step farther to say that we can effectively mitigate the problem by radical geoengineering means is a step way beyond credibility. That we SHOULD d

This. The falling sky proponents love to pretend that it's all a done deal yet the entire model fails to adequately account for previous warm periods, nor the fact that CO2 is merely plant food. (photosynthesis, how does it work?)

Even if you accept the premises that 1) the climate is warming and 2) that human produced CO2 is to blame, taking the entire thing a step farther to say that we can effectively mitigate the problem by radical geoengineering means is a step way beyond credibility. That we SHOULD do such a thing is absurd in the extreme.

The law of unintended consequences patiently waits.

You think it's a bad idea to seed the oceans with iron, because our interfering with the natural ecosystem might have unintended consequences. So instead, you're suggesting that we should do nothing to stop our interfering with the natural ecosystem by pumping huge amounts of CO2 into the air.

The falling sky proponents love to pretend that it's all a done deal yet the entire model fails to adequately account for previous warm periods, nor the fact that CO2 is merely plant food. (photosynthesis, how does it work?)

In fact, modern climate theory quite well account for climate over the period for which we have reliable information on both global temperature and drivers of climate such as solar radiation and CO2, including the impact of "natural experiments" such as volcanic eruptions. Estimating cli

Yes, I should consider the opportunity cost, and so should you. The annual cost of global warming and the annual cost of mitigation are comparable according to the IPCC. But global warming costs only start having to be paid decades from now, while mitigation efforts have to be paid for now, on a massive scale.

If we mitigate, that money is available for economic growth around the world and the development and deployment of new technologies. That's the opportunity cost we pay, namely the opportunity for th

What they've said is "We shouldn't have done this." Ok, fair enough, nothing wrong with that but that isn't a solution. Telling someone that what they did to cause a problem shouldn't have been done is all well and good, but doesn't solve the problem, it isn't really that useful.

It would be like going to the doctor because you'd broken your arm and having him say "Well you really shouldn't have fallen off your bike, had you not done that, your bone wouldn't be broken. You shouldn't ride your bike at all in

No economist will say, "the economy can grow indefinitely." They WILL say, "we don't know how much it can grow."

Which effectively amounts to the same thing, since it inevitably gets interpreted that way by the numbskulls that lead Western nations. There is a huge difference between accepting that "theoretically" growth is limited (but implicitly assuming that any limits are a very long way off) and understanding that we are now close to the limit, even if we don't know exactly how close.

It's like the difference between saying "We don't know and we don't care" and "We don't know, we'd better find out ASAP".

Fundamentally nobody is willing to do what it takes to deal with carbon emissions...it's perceived as too expensive.

On the other hand, geoengineering solutions (if they work) would be cheap. I heard an estimate that a fleet of small autonomous ships spraying seawater into the air (to seed clouds and increase albedo) would cost ~6 billion. That's nothing in comparison....there are individuals that could afford that.

The basic problem I can see is that the ocean is a complex set of currents that moves nutrients around. Dumping a compound into the ocean at one point to encourage algae blooms may sequester carbon in that location but it also locks up other nutrients as well that would have normally travelled to another part of the ocean. Now maybe such an action will disturb the proliferation of jellyfish somewhere but it's more likely that the missing nutrients will simply impede the growth of algae in another location where, instead of simply dying and sequestering carbon at the bottom of the ocean (from which it will eventually bubble up as methane at some future time) the algae would have provided the base of some local food chain. SO, in short, we lock up both carbon and nutrients in some normally unused part of the ocean while starving another part of the ocean for nutrients.

Yeah, terraforming is an interesting science but it's a risky one when you only have one test case and every bit of life you know of in the universe lives in that single test case.

But, I did see reports of the earlier test case and the motivation behind it. It wasn't really all about saving the planet as much as it was about creating a measurable amount of carbon credits that had a solid monetary value. That was the real motive, creating a way to manufacture carbon credits for sale. The test was done to see if they could find the ratio of carbon sequestered per ton of iron compound dumped into the ocean. That way they could dump a known amount of iron in the ocean and then sell a calculated amount of carbon credits on the carbon credit exchange.

"I always worry about these ideas, they seem good in theory, but in reality you can just end up with a cane toad problem..."

Mod parent up.

Without any doubt. FAR more study would have to be done, over a LONG period of time, before any direct messing with the ecology should be attempted.

I live near a lake that was once called, by National Geographic, one of the 12 most beautiful lakes in the world (and it is a rather large lake, as such things go). And there were wonderful fish in the lake; salmonids, plentiful and tasty.

Local businesses, recognizing that fishing was a major tourist attraction, pressured the state Fish & Wildlife Commission to "improve" the fishery.

I could go on for a long time. But suffice it to say that they did one thing that was well-intended, and supposed to help the fish population. But it had unintended consequences. Then they fooled with the ecology again, to try to fix their first fuckup, but THAT had unintended consequences. Then they did it AGAIN, to fix that one, and THAT had unintended consequences.

The long and short of it is: they averted total disaster from their first mistakes, but the fishery is nowhere near as healthy and strong and plentiful as when they first tried to intervene. And yes, it is all directly attributable to their actions.

BE VERY CAREFUL BEFORE YOU FUCK WITH THE ECOLOGY. THE LAW OF UNINTENDED CONSEQUENCES IS LIKELY TO BITE YOU IN THE ASS.

We have seen this in so many different ways. These people should have their heads examined if they propose to do it anytime soon. Long-term study is needed, even if things get bad. Anyone who tries it before thorough long-term studies are done is probably deserving of being taken out and shot.

"In all seriousness, why do you feel the need to keep the name of the lake a secret? Is it because you are pulling your entire story out of your ass? The environment is quite an important thing to say the least, but lying does not help your agenda if you truly support serious environmental evidence and action."

In all seriousness, it's because I don't want YOU to know where I live, dumbshit.

That seems almost certain, because there is no such lake ranking published by NG. It's like all the hills in England and Wales being known for sure by the locals as the site of the battle of Mount Baden. Popularity never hurts, does it?

Seems no more far-fetched than the current plan, which is assuming world leaders of developed and developing nations can all agree to limit the economic function and development of their respective countries, and not fall into a prisoner's dilemma.

Kyoto etc. might have worked if there was a crash research program into viable clean sources of power (eg fusion) and battery tech back in the 90s. As it is, there wasn't, we have no reasonable way of both (1) keeping our lifestyle and (2) meeting Kyoto targets.

_Something_ has to be done; if the idea in TFA is based on sound science, why not give it a go. Start slow, maybe, but at least try.

The sad thing is, even if we'd met Kyoto, it would have made little difference to the overall human CO2 emissions. Kyoto wasn't anywhere near enough to turn things around, and anything more would have caused economic damage.

The current plan seems to be "do nothing big enough to stop a massive extinction event, but do lots of little things around the edges that make people feel better while we all slip past the point of no return."

I'm not enthusiastic about most of the geoengineering ideas floating around today, but I suspect we're going to end up needing some of them. In that light, lots of experiments now to understand as much as we can before we're forced to use one or more of them seems prudent.

I don't understand this. If you believe that the consequences of AGW are on the scale of catastrophic mass extinction events then you should be very enthusiastic about geoengineering. If the entire species is going to die, I'd be pretty enthusiastic about anything that might help.

What I guess I'm saying is that there is a disconnect (or at least I perceive one) between the urgency of AGW when it comes to pleas for emissions reductions on the one hand, and the tepid response to these sorts of projects. I do

"What I guess I'm saying is that there is a disconnect (or at least I perceive one) between the urgency of AGW when it comes to pleas for emissions reductions on the one hand, and the tepid response to these sorts of projects."

That's easy to explain: even many of the people who profess that CO2-based climate change is "proven", still don't actyally believe it enough that they want people messing with their environment.

No "prisoner's dilemma" involved for the politicians: voters in the US and Europe would be tearing their politicians apart over the costs of global warming mitigation. Just look at all the belly-aching over the current recession.

We could find a way to trigger a super volcano. This would also help to curb global warming.We could create a nuclear winter by setting of several giant nuclear weapons over the countries of choice. This would also reverse global warming.There are lots of things which we could do, but doesnt mean we should.Considering that we do not know the extent of the oceans impact on global weather patterns, we may do well enough to leave them alone until we do.

Since everything we do destroys something on the planet, I'm gonna go ahead and call this one right now. Algea blocks sunlight below, kills seabed plants in shallow areas and kills...I dunno, Nemo or something in deep water by lowering the temperature, making automatic frozen fishsticks.
This did sound like one of the better theories for fixing the problem extremely quickly and cheaply when I heard about it on TV though.

And ice floats, so no frozen deep-water fish. And we desperately need to make the oceans a little cooler - and get the CO2 out of them.

Don't get me wrong: the only good solution is to stop pouring CO2 into the air. But, given that humanity is too dumb to do that, this seems like the nearest thing to a workable solution I have heard. Do enough of it, and we might get ourselves some oil, but we might have to wait until the 20,000th century.

Let's convert carbon dioxide to methane,that's sure to help...Excessive growth of algae (influenced by global warming and fertilizers washed down to the sea from farmlands) is a part of the problem, not the solution.

The problem with algae is that while, true, they convert CO2 to oxygen, they do so, by growing - building their own mass.There's only so much of ocean surface where they can grow by absorbing light. The excess algae not receiving enough light die and rot. And they produce methane by rotting.

Parent is right.
According to wikipedia (because I am feeling a bit lazy,there are plenty of other sources out there).

For example, on a molecule-for-molecule basis the direct radiative effects of methane is about 72 times stronger than carbon dioxide over a 20 year time frame[13] but it is present in much smaller concentrations so that its total direct radiative effect is smaller, and it has a shorter atmospheric lifetime

The interesting thing is that after the shorter atmospheric lifetime that they are talking about here. Methane breaks down into CO2 (!) and Water.
Which means that Methane is actually a double whammy for global warming.

Yep, lock up our atmospheric carbon at the bottom of the oceans where we can't get to it. Wouldn't it be better to find a way to directly capture it from the air (through electrolytic deposition or something) so that it can be used by the impending graphene and carbon nanotube industries?

The team reports that much of the captured carbon was transported to the deep ocean, where it will remain sequestered for centuries - a 'carbon sink'

This sounds like a good quick patch (in the ecological time scale), but do we need that carbon? Seems like moving carbon from the Earth's crust to the deep ocean could have some long-term ramifications. I'm not sure I know enough about the subject even to qualify as an amateur, but it seems like it would be more profitable in the long run if we could grow plant

The rest of the developing world is going to follow this pattern. Soon we'll all be emitting high amounts of carbon, but even more, each of us will require a lot of land for our lifestyles. Not just our homes, but roads, hospitals, shopping, parking, schools, storage, government buildings, etc.

For every person we put on this earth, there's less space for the natural world and its forests and oceans which renew our air and water. Earth is finite; humans are acting like its capacity to have new humans is infinite.

We're all in denial of how simple this is. There are too many people. We're making even more. At some point, we will have used up enough land so that pollution, species loss and loss of renewable resources makes us get a Darwin award as a species.

So cutting down the trees that remove CO2 from the atmosphere, expending energy to turn them into disposable goods, driving them across the country in polluting vehicles, then disposing them in the trash is helping the environment?

The trees wouldn't be grown in the first place if not for the demand for these consumer products. The majority of lumber in the US is harvested not from old growth, but from tree farms.

And trees absorb more CO2 when they're in their fast growth phase. So cutting them down and re

Didn't I just recently hear about the idea to seed iron to fight global warming. Right, it was the Panchaea project [wikia.com] in Deus Ex Human Revolution. Well I just hope it works out better than it did in the game though:P

Seeing as how 1/3 of the earth is made of iron and we've assuredly been rained upon by some iron meteorites that probably popped somewhere in the atmosphere, something tells me that iron-rich moments in the ocean's history have not been unknown. Does the fossil record have anything to say on the subject?

Seeing as how 1/3 of the earth is made of iron and we've assuredly been rained upon by some iron meteorites that probably popped somewhere in the atmosphere, something tells me that iron-rich moments in the ocean's history have not been unknown. Does the fossil record have anything to say on the subject?

Someone is destroying your entire ecosystem, and telling you "we can't stop doing that, because we would lose money." And someone else says, "well, maybe if we cause a corresponding rapid radical transformation in ocean ecology it will offset the other catastrophe". And your answer is "hmm, yeah, that might work."

The denialist throw a lot of bullshit at the theories and observations of global warming, one of which is how little we know because we only have reliable info for ( pick one ) 20, 30, 50, 70, 100 years.

And then, they dream up a bunch of half-baked, cockamamie predictions based on scanty data, weak facts, implausible records, oh, and simplified models ( that's a good one, considering how much they think climate models are unreliable) of st

I suggest you go read the IPCC's disscusion on attribution in its reports before attempting to attack the conclusions. The +/- forcings due to changes in solar fux are swamped by the +/- forcings due to human activity to such an extent that it is difficult to detect any signal in the data. The areosols released by China alone do far more to cool the planet than changes in solar flux. Also your assumption that solar flux caused the little ice age is not supported by the data, solar fux is the least understoo

Ah, the it's all cyclic - meme. That's a rather new one, isn't it? Of course, since there is no actual periodic cause to be found for the current warming trend, you gotta heap cycles upon cycles to get an arbitrary match to the data. I suspect that someone in the denialsphere lately discovered Fourier analysis without having a clue what it is actually good for. Starting from there, it got amplified by the usual blogorrhoea.

There is only one way to be sure, but unfortunately it isn't available to us. Outer Space Treaty prohibits deployment of nuclear weapons in orbit. But the scientific evidence seems to at least strongly imply that the problem exists and may not be entirely harmless.

It is a risk management issue. We know there is a risk of global warming. We know it can potentially bring massive (earth altering amounts) losses if unmitigated. The question is do we wait uninsured, or do we consider an insurance policy of some sort.

To give you a car analogy, the situation is a bit like driving in a thick fog with high speed. You know that there may be obstacles ahead of you. You know it will be deadly if you hit one. You know you'll have a very short time to react when you clearly see one. What is smarter to do, slow down until the fog clears, or keep pressing the accelerator just because you enjoy high speed?

It was good up until that part where people "enjoy high speed". It is more that they don't want to slow down because they are being chased by something possibly deadly.

This is so common it is like a meme. You have arbitrarily set the cost of global warming to infinity, and the cost of "fixing it" near zero, thus leading to a useless cost-benefit analysis. Meanwhile you think you are more informed and intelligent than the "deniers". Read the IPCC AR4, they do a pretty good one.

It is more that they don't want to slow down because they are being chased by something possibly deadly.

What is this deadly thing that is chasing humanity and necessitates the environmental destruction of the past 100-150 years?

You have arbitrarily set the cost of global warming to infinity, and the cost of "fixing it" near zero, thus leading to a useless cost-benefit analysis.

No, it is you who arbitrarily sets the cost of the consequences of global warming to zero and the costs of mitigation policies to infinity. I am ready to admit the outcomes are uncertain, but I also think the risk estimates we have do necessitate a mitigation strategy of some sort.

This always confuses me. Why do people seem to think that climate scientists advocate deindustrialisation? I have never heard a serious case arguing for it. And yet, many arguments against global warming measures seem to claim that that is what is being proposed. Wherefore this misconception?

Because many arguments comes from environmentalists, who frequently argue for human suffering if the alternative is environmental problems, rather than climate scientists. They cannot fathom just how much depended we are on current industry and how impossible it is to replace it with something even marginally less efficient without huge amount of human suffering.

Why do people seem to think that climate scientists advocate deindustrialisation? I have never heard a serious case arguing for it.

It's generally the environmentalists yelling about global warming the loudest, and shortly thereafter telling everyone that the solution is to go back to living in caves (quite literally).

But it's not a complete misconception... Scientists don't quite say it, but it's clearly implied, because seriously reduced consumption and activity is currently the only way to make as big of a dent in CO2 production as they advocate.

There are major things like cement production, which alone emits about 6% of total man-made greenhouse gases, for which there seems to be absolutely no possible option to significantly reduce the CO2 emissions, other than simply stopping cement production. With cement being one of the most important construction materials, this directly translates into stopping most large building construction, and a severe economic crash.

Actually, I've found it's the people doing the polluting who claim that polluting less would mean everyone would have to go live in caves, I can't say I've ever heard a serious environmentalist argue we should do so*.

* Excepting the one group that advocates building homes in caves, but to be faire, the caves they want people to live in are better than the houses that most people live in now.

There are major things like cement production, which alone emits about 6% of total man-made greenhouse gases, for which there seems to be absolutely no possible option to significantly reduce the CO2 emissions, other than simply stopping cement production. With cement being one of the most important construction materials, this directly translates into stopping most large building construction, and a severe economic crash.

The goal is to reduce overall emissions to a sustainable level, they don't need to be cut to 0. Imagine for a moment

It is a risk management issue. We know there is a risk of global warming. We know it can potentially bring massive (earth altering amounts) losses if unmitigated.

According to the IPCC report, the losses are not "massive", they amount to a few percent of global GDP, comparable to how much it would cost to mitigation. The losses for the US and Europe are even smaller.

Global warming is something we can live with: it causes changes, will impose some costs, but it is not a civilization killer. (Global cooling, on the other hand, is a huge problem. The US and Europe would be in deep trouble if climate went back to the way it was a few thousand years ago.) And carbon emissions will abate over the next couple of decades anyway, as solar and other technologies become more attractive and cheaper.

The question is do we wait uninsured, or do we consider an insurance policy of some sort.

I'm pretty sure dumping massive quantities of iron into the ocean and causing algal blooms is not "insurance", it is pollution.

Since when is it economic alarmism when someone wants to shutdown the economy?

So who is this someone? - Other than the "tear it all down and start again" types who turn up at tea party rallies and OWS sit-ins, I don't know of anyone who wants to "shutdown the economy"? If you are so certain about your basic assumption, surely you can give us a name and point to their published economic analysis? In fact if you are certain your claim is not alarmisim I would expect you would would also be able to point to an overwhelming consensus among working economists. AFAIK published economic modelling generally predicts a worst case senario of a 0-10% drop in global GDP over a 50yr period. To put that into perspective global GDP has more than doubled since 1995.

A real skeptic questions their own assumptions which is how (over a 30yr period) I became convinced that burning all known FF deposits would be a catastrophic course of action, as a grandfather of three toddlers I am seriously fucked off that burning every last bit of coal, gas, and oil we can find is exactly what we are planning to do for no other reason than preserving the bussiness model of some very rich and powerfull luddites [wikipedia.org]

OTOH: I'm probably talking to a young "free market" ideologue who didn't hear the FF industry "cry wolf" when Nixon introduced the clean air act, or Reagan introduced cap and trade on sulphur emissions, or whoever it was that took the lead out of petrol. So I don't really expect my little rant will persuade you to question yourself. Besides being wrong would imply you have been recruited as a "useful idiot" by someone you already trust, and nobody likes to admit they have been fooled by what others see as obvious propoganda.

Not true. The world was on a cooling trend until the industrial revolution.

And the Earth has been far hotter on average than it is today

So? Who cares what the temperature was like at some arbitrary point in the distant past? Species change, ecosystems change. What matters is the *rate change*, because adaptation doesn't occur instantaneously. It's the rate change that's concerning. The last time Earth saw this sort of rate-change was the Paleocene-Eocene Thermal Maximum [wikipedia.org]. The world was left as uch a d

I took a course on oceanography a few years ago, and we actually studied this. I'll summarize my professor's powerpoint notes as best I can.

Iron is a limiting nutrient in phytoplankton growth. This is not in dispute. However if we are to add iron to the ocean in order to increase phytoplankton counts, and thus to increase CO2 uptake then we must consider several things. Firstly, how much CO2 will be semi-permanently transported to the ocean floor. In terms of percentages, if increased phytoplankton counts caused a CO2 flux in the surface layer of 50 Gt Carbon / year, the corresponding CO2 flux to the ocean floor would be about 0.7 Gt Carbon / year. This is due to the fact that the mechanisms of carbon transport from the surface to the sea floor (the "biological pump") is quite inefficient. Thus the increase in phytoplankton at the surface would have to be HUGE to transport meaningful amounts of CO2 to the sea floor.

Secondly, there may be dire unintended or undesired consequences of increasing the surface phytoplankton counts. Imagine we put significant amounts of iron in the ocean and imagine that surface phytoplankton counts increased significantly. At the surface we could get increased CO2 uptake and O2 production. But what happens when those phytoplankton die? They sink. And when they sink to deeper layers, other organisms would decompose them. Those decomposers would be oxygen breathers and would consume oxygen at the deeper layer. If their numbers increased due to increased dead phytoplankton, the decomposers could deplete the O2 levels in that level, creating anoxic zones at deeper levels in the ocean. In addition, some of these decomposers might be methane producing bacteria, especially in the absence of oxygen. That methane might make its way into the ocean. The worry is that the imbalanced increase in phytoplankton might result in an anoxic jellyfish ocean that would be rather unfriendly to fish like salmon, tuna, and the other common species that currently exist.

Unless the above arguments have been refuted, I don't know why iron fertilization is still being pushed as a realistic option. It seems to me that many decision makers are nearly completely illiterate in science.

It seems to me that many decision makers are nearly completely illiterate in science.

You're just figuring this out? I realized decades ago that the type of education needed to become a successful politician is completely different from that needed to understand science and that almost anybody planning to go into politics would regard studying science to be a complete waste of their time.

Stepping into a mine field here, but that's what I was wondering. This appears to be a proposal to remove carbon, rather than reduce adding carbon - that's fine, but is it sustainable? And is the carbon sequestered at the bottom of the ocean more or less "locked up" than it would be in trees or tar or oil?